If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

SB3 volume output lower on left than right channel - please help

Have an SB3 that is unfortunately out of warranty. The volume output is different (lower on left than the right channel) both through the rca outputs and also the headphone socket on the SB3.
Have tried updating the firmware and returning the unit to factory settings but neither helped.
I suspect a hardware problem but have not been able to find any reference to similar issues on the forum with the SB3.
Anyone have an idea where the problem might lie? Might it be a simple job to trace to the faulty circuit part and component that is causing this?

I haven't done any tweaks and the L&R channel output imbalance remains the same whatever the volume output level.
For those that know the SB3, is there a particular part of the circuit / component that is likely responsible for the output difference?
Would send for servicing here but understand that where I live, Singapore, Logitech don't support SB3 servicing.

thanks for the responses. if I get bold enough might open it up or let an electrician friend of mine take a look at it.
the left channel out put is not at all distorted just a lower in volume than the right. I would use balance but my pre-amp doesn't have it and the software plugin that I found for the SB3 to alter volume balance between left and right loads but doesn't have any effect.
Shame they don't service it here and also that the SB3 is now hard to buy new as well. not keen on the duet really. oh well, will try and find one in the UK rather than here in Singapore.

Appreciate the link and suggestions. Have replaced ICs and capacitors in other equipment before so am confident of doing the repairs. Any pointers for how to confirm if either of these are indeed the faulty components?

Appreciate the link and suggestions. Have replaced ICs and capacitors in other equipment before so am confident of doing the repairs. Any pointers for how to confirm if either of these are indeed the faulty components?

Play a sine wave test tone and measure RMS volts to ground, before and after the caps. If the left is different from the right before the caps, then it's the DAC, if it's different after the caps then its the caps. I might be oversimplifying, but that's where I would start.

This has given me the required knowledge to fix my SB3 which was showing a 20dB loss on the left channel. The fault did, indeed, turn out to be the decoupling cap between dac and op amp.

As a quick fix, I removed the decoupling cap, eliminating the op amp from the circuit, and took the dac output directly to the second decoupling cap, immediately prior to the lp filter at the output sockets.